. Appleton's dictionary of machines, mechanics, engine-work, and engineering. that edge, the work is at one sweep reduced nearly to its re-quired diameter by a wide thin cut, which may be compared with a chamfer, or a conical fillet, con- TOOLS, TURNING. 767 necting the rough external surface with the smooth reduced cylinder. Therefore after the first entry,the point of the tool is buried in the clean metal below the crust, and works laterally, which is indeedthe general path of pointed tools for metal. When the graver is used in the turn-bench with intermittent motion, as for the pivots of wa
. Appleton's dictionary of machines, mechanics, engine-work, and engineering. that edge, the work is at one sweep reduced nearly to its re-quired diameter by a wide thin cut, which may be compared with a chamfer, or a conical fillet, con- TOOLS, TURNING. 767 necting the rough external surface with the smooth reduced cylinder. Therefore after the first entry,the point of the tool is buried in the clean metal below the crust, and works laterally, which is indeedthe general path of pointed tools for metal. When the graver is used in the turn-bench with intermittent motion, as for the pivots of watches, theaxes for sextants, and other delicate works, it is applied overhand, or inverted, as in Fig. 3612; but itis then necessary to withdraw the tool during each back stroke of the bow, to avoid the destruction ofthe acute point, and which alone is used. The graver, when thus applied in lathes with continuousmotion, is only moved on the rest as on a fulcrum, and in the plane in which it lies, rather as a test ofwork done, than as an active instrument. 3612. 3613. The edge of the graver is afterwards used for smoothing the stronger kinds of work ; it is then neces-sary to incline the tool horizontally, to near the angle at which it is ground, in order to bring the slopingedge parallel with the surface. But the smoothing is better done by a thick narrow flat tool, groundat about sixty degrees, the handle of which is raised slightly above* the horizontal, as in Fig. 3613, inorder that its edge may approach the tangential position; here also the tool is rotated on one edge,after the manner of the brass tools or the graver. For many slight purposes requiring rather delicacy than strength, as in finishing the rounded edgeof a washer, the flat tool is inverted or placed bevel upwards, as in Fig. 3614 ; the lower side then be-comes the tangent, and the edge the axis of rotation of the tool, the same as in turning convex mould-,ings with the soft-wood chiseL Indeed, many anal
Size: 3095px × 808px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectmechanicalengineering, bookyear1861
